package com.orhon.smartcampus.utils;

import java.net.InetAddress;
import java.net.UnknownHostException;

import javax.servlet.http.HttpServletRequest;

public class IPUtil {  
     /** 
      * 获取用户真实IP地址，不使用request.getRemoteAddr();的原因是有可能用户使用了代理软件方式避免真实IP地址, 
 *  
      * 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值，究竟哪个才是真正的用户端的真实IP呢？ 
      * 答案是取X-Forwarded-For中第一个非unknown的有效IP字符串。 
      *  
      * 如：X-Forwarded-For：192.168.1.110, 192.168.1.120, 192.168.1.130, 
      * 192.168.1.100 
      *  
      * 用户真实IP为： 192.168.1.110 
      *  
      * @param request 
      * @return 
      */  
    public static String getIpAddress(HttpServletRequest request) {  
    	String ipAddress = request.getHeader("x-forwarded-for");
		if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
			ipAddress = request.getHeader("Proxy-Client-IP");
		}
		if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
			ipAddress = request.getHeader("WL-Proxy-Client-IP");
		}
		if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
			ipAddress = request.getRemoteAddr();
			if(ipAddress.equals("127.0.0.1") || ipAddress.equals("0:0:0:0:0:0:0:1")){
				//根据网卡取本机配置的IP
				InetAddress inet=null;
				try {
					inet = InetAddress.getLocalHost();
				} catch (UnknownHostException e) {
					e.printStackTrace();
				}
				ipAddress= inet.getHostAddress();
			}
		}
		//对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
		if(ipAddress!=null && ipAddress.length()>15){ //"***.***.***.***".length() = 15
			if(ipAddress.indexOf(",")>0){
				ipAddress = ipAddress.substring(0,ipAddress.indexOf(","));
			}
		}
		return ipAddress; 

    }  
       
 }  